I am no big expert and unlike others who claim and point out things that are not true, I'd say you should have a strategy to make small investments from time to time. Who knows, if by chance, the market booms from April? The initial small investments you already made should be helpful in giving you profits already. Waiting to invest, and waiting with some investment made are two different things and you should try to choose the latter in that case.
Also, never put all the eggs in the same basket and at one time. Try for smaller investments on a timely basis. Good luck